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Advantages of the ZIMO DCC system
ZIMO represents the most advanced end of DCC. We always try to find and to implement the very best solution for any element of the system, beginning with the system architecture up to the software control.
While offering all high level standard features of the DCC world, ZIMO has additional characteristics, which make the system stand out from rival products. This is a (possibly incomplete) list of such features:
Multi protocol operation (NMRA-DCC and MOTOROLA). Stabilized and adjustable (12 to 24 V) track voltage. Programming track with capability to operate trains. Built-in volt and amp meter. Multifunctional cabs (handhelds) including loco and accessory operations programming, routes, block control, etc. Bidirectional communication for wireless cabs (infrared and radio). Virtually noiseless and very smooth way of driving the locomotive motors. Function mapping not only corresponding to, but going beyond the NMRA recommendations. Prototypical slow illumination and dimming of signal lights. AND the very unique "Signal controlled speed influence" and loco number identification.
The most outstanding features of the ZIMO system:
ZIMO offers many advantages (like powerful start sets, wireless cabs, supersonic decoders, etc.), but there are two outstanding features, which make the big difference between ZIMO systems and all other digital systems:
Both, the "signal controlled speed influence" and the "loco number identification" has been used for many years in ZIMO systems with the "old" ZIMO data format; now they are also implemented in the NMRA-DCC compatible ZIMO system, even in an improved version.
Realistic railway operation with “signal controlled speed influence”:
Signal controlled speed influence" describes a method to stop or to apply speed limits to trains on certain track sections depending on actual circumstances of operation (e.g. state of signals). The stop information and speed limit information has to be accepted by all locos independent of their decoder address.
Different ways (other than ZIMO´s):
The “conventional” method: The power supply to the track section belonging to the red signal is switched off. Disadvantages: lights are off (also sound, etc), no control over train as long as signal stays red.
The computerized method: The actual position for all trains is calculated at all times by a computer; the speed influence is made via normal commands. Disadvantages: Computer and a lot of associated equipment (occupancy detectors, etc.) distributed all over the whole layout is necessary right from the beginning; no unrestricted (manual) operation of trains possible, as computer would lose track of the position of train.
The brake generator method: In certain track section the digital control information is replaced by broadcast commands which only contain speed information. Disadvantages: no control over the train from the cab during stop; complicated setup to avoid bridging the gap (both-rail) between sections by locos and cars.
ZIMO´s special way of“signal controlled speed influence”:
Speed limits bits (stop and 5 speed steps) are fed into the data stream, which do not replace the individual loco instructions coming from the cabs. So all disadvantages mentioned above can be avoided and some good features are added:
- full control over headlights and other loco functions (steam, sound, etc.) is maintained at all times, even when stopped at a red signal and on sections with restricted speed
- overriding the signal controlled stop or speed limit is possible from the cab with the special key “MAN”
- acceleration and deceleration of locos is adjustable on an individual basis (by special configuration variables which are added to the normal NMRA set only in ZIMO decoders)
- bridging the isolation gap between adjacent track sections does not cause short circuits or undefinable conditions.
ZIMO´s “signal controlled speed influence” is an economical method, too: no additional hardware is needed within the decoders (which is very important because of space limitations), and rather simple electronic circuitry in the track section modules MX9 allow application of speed limits to track sections.
For computer controlled layouts the "STP" SOFTWARE takes advantage of this special ZIMO feature: The computer has no need to internally trace train numbers across the layout. No control commands are issued directly to any loco decoder; instead trains are controlled via track sections. So manually driven trains as well as manual interventions are considered automatically.
Loco number identification:
Each loco decoder acknowledges the receipt of a command addressed to it with a special pulse on the rail. This pulse is detected by track section circuits, which give information about the actual location of the locos.
System architecture - The CAN-Bus
One of the most important characteristics of a DCC system is the data link (the "Bus") between the system components like command stations, cabs, modules for feedback information, etc. The differences among the systems in this respect are not to be seen when starting with a DCC application, but they will be crucial when expanding the control system. Well-known bus systems are the X-Bus (used by Lenz, Arnold), the Loconet (used by Digitrax), the NCE-Bus (used by Wangrow/RamTraxx), and the CAN-Bus (used by ZIMO/STP).
The ZIMO CAN-Bus is probably the most powerful and reliable data link used in model railroad control today. It works as a Local Area Network (LAN) with multi-master capability, there is no time-consuming polling by a central device.
HIGHEST SPEED (115 kbit/s):
This is more than any of the rival systems offer. Although a bus with lower speed would be sufficient if used as cab bus only, the ZIMO CAN-Bus shows its superior performance if e.g. hundreds of occupancy detectors and loco number identification boards have to transmit continually changing information to a computer (or to several computers). Because of this high performance the ZIMO system needs not to use separated cab and feedback buses, but all data transmission is done within one network.
HIGHEST RELIABILITY:
The CAN-Bus hardware and software protocol is widely used in industrial, automotive and medical applications. The physical layer is similar to the well-known RS-485 standard, but with special capabilities in order to handle heavy traffic efficiently. Extensive automatic error recognition and correction are included in the CAN protocol. Error counters, which are provided in the micro controllers of all cabs and modules, allow successful problem diagnosis, if this should be necessary at some time.
FREE TOPOLOGY FOR MOST APPLICATIONS:
Only in case very large cabling length (up to several hundred meters = about 1000 feet) the CAN-BUS should be installed as a "linear terminated bus", that means wiring point to point rather than a tree with branches and placing resistors at both ends of the network. In most applications (up to 50 m, but more likely up to 100 m) trees and branches are allowed without any restrictions.
EASY TO WIRE:
The ZIMO CAN-Bus uses 6 pin TelCo type connectors and ribbon cable. The CAN-Bus itself needs only 2 wires; the cable contains also power supply for cabs and modules and various "grounds". CAN-Bus cables in various lengths are available from ZIMO.
Alternatively the user is able to make his own cables by means of a special mounting tool (also available from ZIMO, or Your local electronic supply store). This should be used for larger layouts (wiring of accessory modules, track section modules, etc.) in order to avoid waiting on shipments (and of course it is cheaper, too).
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